1. Field of the Invention
The invention relates to a tilt steering apparatus for vehicles.
2. Description of the Prior Art
A conventional tilt steering apparatus for vehicles, for example as shown in Japanese Koukai U.S. Pat. No. 57-155156, fundamentally comprises a fixed bracket fixed on a vehicle body, a rotatable bracket pivotably mounted on the fixed bracket and supporting a steering wheel structure, a pawl mounted on one of the fixed bracket and the rotatable bracket and being engageable with and disengageable from a ratchet formed on the other of the fixed bracket and the rotatable bracket so as to secure the rotatable bracket on the fixed bracket, a manual operating lever pivotably mounted on the other of the fixed bracket and the rotatable bracket and operatively connected with the pawl through a cam mechanism provided between the pawl and the manual operating lever so as to engage between the pawl and the ratchet and disengage the pawl from the ratchet. Therefore, by operating the manual operating lever, the pawl is disengaged from the ratchet and the rotatable bracket becomes rotatable or tiltable.
In the conventional tilt steering apparatus, however, the manual operating lever projects from a steering column. Therefore, the outer appearance thereof is unappealing. Further, the manual operation of the manual operating lever is very troublesome.
Besides, the cam mechanism is used between the manual operating lever and the pawl. Therefore, when the ratio of the length between the cam portion and the pivoting portion to the length between the grip portion and the pivoting portion in the manual operating lever is large, the grip portion and the pivoting portion in the manual operating lever moves within the small area but the cam mechanism becomes large. While when the above ratio is small, the cam mechanism becomes small but the grip portion moving area becomes large. Also, at this point, the tilt steering apparatus becomes large.